thelounge/client/js/slideout.js

99 lines
2.1 KiB
JavaScript
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"use strict";
const menu = document.getElementById("sidebar");
let touchStartPos = null;
let touchCurPos = null;
let touchStartTime = 0;
let menuWidth = 0;
let menuIsOpen = false;
let menuIsMoving = false;
class SlideoutMenu {
static enable() {
document.body.addEventListener("touchstart", onTouchStart, {passive: true});
}
static toggle(state) {
menuIsOpen = state;
menu.classList.toggle("menu-open", state);
}
static isOpen() {
return menuIsOpen;
}
}
function onTouchStart(e) {
if (e.touches.length !== 1) {
onTouchEnd();
return;
}
const touch = e.touches.item(0);
menuWidth = parseFloat(window.getComputedStyle(menu).width);
if ((!menuIsOpen && touch.screenX < 50) || (menuIsOpen && touch.screenX > menuWidth)) {
touchStartPos = touch;
touchCurPos = touch;
touchStartTime = Date.now();
menu.classList.toggle("menu-dragging", true);
document.body.addEventListener("touchmove", onTouchMove);
document.body.addEventListener("touchend", onTouchEnd, {passive: true});
}
}
function onTouchMove(e) {
const touch = touchCurPos = e.touches.item(0);
let setX = touch.screenX - touchStartPos.screenX;
if (Math.abs(setX > 30)) {
menuIsMoving = true;
}
if (!menuIsMoving && Math.abs(touch.screenY - touchStartPos.screenY) > 30) {
onTouchEnd();
return;
}
if (menuIsOpen) {
setX += menuWidth;
}
if (setX > menuWidth) {
setX = menuWidth;
} else if (setX < 0) {
setX = 0;
}
menu.style.transform = "translate3d(" + setX + "px, 0, 0)";
if (menuIsMoving) {
e.preventDefault();
e.stopPropagation();
}
}
function onTouchEnd() {
const diff = touchCurPos.screenX - touchStartPos.screenX;
const absDiff = Math.abs(diff);
if (absDiff > menuWidth / 2 || Date.now() - touchStartTime < 180 && absDiff > 50) {
SlideoutMenu.toggle(diff > 0);
}
document.body.removeEventListener("touchmove", onTouchMove);
document.body.removeEventListener("touchend", onTouchEnd);
menu.classList.toggle("menu-dragging", false);
menu.style.transform = null;
touchStartPos = null;
touchCurPos = null;
touchStartTime = 0;
menuIsMoving = false;
}
module.exports = SlideoutMenu;